The Relationship Between Resting Heart Rate and Cardiovascular Risk Factors Among Adults Aged 18 Years and Above in...

(1) Background: Resting heart rate (RHR) is an easily measurable cardiovascular risk indicator, yet its relationship with cardiometabolic risk factors remains understudied in rural African populations. This study investigated the association between RHR and cardiovascular risk factors among adults in the rural Ellisras community, South Africa. (2) Methods: A cross-sectional analysis was conducted among 629 participants (306 males, 323 females) aged 18 years and above from the Ellisras Longitudinal Study. Anthropometric measurements, blood pressure, biochemical parameters, and lifestyle factors were assessed. RHR was categorized as normal (60-100 bpm), bradycardia (<60 bpm), or tachycardia (>100 bpm). Statistical analysis included descriptive statistics, chi-square tests, Pearson correlations, and logistic regression to identify predictors of abnormal RHR. (3) Results: The mean age was 25.55 ± 1.97 years, with significant gender differences in cardiovascular parameters. Females had higher RHR (81.78 ± 11.73 vs. 70.36 ± 12.89 bpm, p < 0.001), body mass index (BMI) (24.62 vs. 20.67 kg/m², p < 0.001), and waist circumference (WC) (81.00 vs. 73.50 cm, p < 0.001). Resting heart rate (RHR) distribution varied significantly by gender (p < 0.001), with bradycardia more prevalent in males (91.3% vs. 8.7%) and tachycardia in females (75.0% vs. 25.0%). Significant positive correlations were observed between RHR and age (r = 0.105, p = 0.009), diastolic blood pressure (DBP) (r = 0.135, p < 0.001), fasting blood glucose (FBG) (r = 0.098, p = 0.016), total cholesterol (TCHOL) (r = 0.168, p < 0.001), LDL-C (r = 0.201, p < 0.001), WC (r = 0.169, p < 0.001), and sum of 4 skinfolds (bicep, tricep, subscapular and supraspinale) and (r = 0.184, p < 0.001). A negative correlation was found with systolic blood pressure (SBP) (r = -0.105, p < 0.001). In the logistic regression analysis, participants aged >25 years had significantly lower odds of abnormal RHR (OR = 0.50, 95% CI: 0.26-0.97, p = 0.039), after adjusting for confounders. In the fully adjusted model, RHR remained significantly associated with DBP (β = 0.59, p < 0.001), LDL-C (β = 2.76, p = 0.008), WC (β = 0.10, p = 0.012), and triglycerides (TG) (β = 2.78, p = 0.002). (4) Conclusions: RHR demonstrates significant associations with multiple cardiovascular risk factors in this rural South African population, with distinct gender-specific patterns. Age emerged as the primary independent predictor of abnormal RHR. These findings suggest that RHR could serve as a valuable, cost-effective screening tool for cardiovascular risk assessment in resource-limited rural settings.